Spring action for firearm hammers



M y 7, 1929- A. R. B RlNK ERH OFF 1,711,874

SPRING ACTION FOR FIREARM HAMMERS' Filed Oct. 26, 1927 m. WM WWW "I J.

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Patented May 7, 19.29. 4

UNITED STATES ARQHIBALD R. BRINKERHOFF, or LOS ANGELES, CALIFORNIA.

- SPRING ACTION FOR FIREARM HAMMEBS,

Application filed October as, 1927. Serial No. 228,930.

My invention relates generally to firearm hammers and more particularly to springs therefor, and it is a purpose of my invention to provide an extremely simple, compact, and

dependable spring action capable of application to all types of firearms and which, when applied to an automatic pistol, for example, dispenses with the comparatively complicated spring action embodied in -the 1o grip of the pistol to the rear of the cartridge magazine, and in the military or heavier type permits the grip, which is bulky and unhandy, to be reduced in size to practically the requirements of the magazine alone, and altered in shape to comfortably fit the hand .of the user so as to allow the trigger fingento reach and properly engage the trigger with ease. It is a further purpose of my invention to provide a hammer spring action wh ch can i be adjusted to vary the spring tension 1mposed on the hammer when cooked, to the end that the force of the blow struck the firing pin by the hammer when released can be 5 varied to suit the requirements of a partlcular firearm.

I will describe only two forms of spr1ng actions for firearm hammers embodylng my I invention and will then point out the novel features in claims.

In the accompanying drawlng, A Fig. 1 is a view showing in vertlcal section one form of hammer spring action applied to an automatic pistol.

:1; Fig. 2 is a partial transverse section of Figure 1, taken on the line 22 of Fig. 1.

Fig. 3 is a partial longitudinal section, taken on the line 3-3 of Fig. 2.

Fig. 4 is a section, similar to Fig. 2, showm ing a modified form of the invention.

Fig. 5 is a section, similar to Fig. 3, showing the same form of the invention and taken on the line 5-5 of Fig. 4.

Referring specifically to the draw ng in which similar reference characters designate similar parts in each of the several VIEWS, and particularly to Figs. 1 to 3 inclusive my invention in its present embodiment is shown for the purpose of illustration applied to a conventional form of automatic pistol having a hammer H mounted in the receiver R 65 However in carrying my invention into prac- [in the receiver It so that with the head in tice the pin is preferably modified to the extent that one end thereof is provided with a head 10 of angular form adapted to seat in a correspondingly shaped pocket 11 formed the pocket, rotation of the pin will be prevented. The pin is also preferably slotted longitudinally from its other end as indicated at 12 and said other end is formed with a threaded bore 13 receiving a retaining screw 14.

To normally urge the hammer H to the released position shown in Fig. 1, for strikingof the usual firing'pin, I provide a spring designated generally at S and in the present instance constructed of a similar length of. r flat spring wire wound in the form of a flat spiral so as to constitute a torsional spring. For the purpose of receiving the spring the pivoted end of the hammer H in the present instance is bifurcated as indicated at 15, the

spring being mounted on the pin P with its inner end angularly bent as shown at 16 and received in the slot 12 of the pin so-as to be fixed against rotation by the latter, while the outer end of the spring is curled and bears igainst the hammer as clearly shown in ig. 1. I In assembling the parts of the spring action the spring S is firstplaced in the bifurcation 15 of the hammer H and the latter then positioned in the receiver B, after which the pivot pin is extended through the receiver and hammer with the angularly bent end 16 of the spring extending into the slot 12. The desired tension is now placed upon the spring by grasping its head 10 with a suitable ine strument and then rotating the pin P in the a direction to -efiect winding of the spring. After the proper tension has been secured 5 the pin is shifted longitudinally until the head 10-seats in the pocket 11 thus locking the pin against rotation and maintaining the spring tension. The retaining screw 14 -is now threaded into-the bore 13 until it bears against the spring and thus co-operates with the head in preventing longitudinal displacement of the pin. The screw also op crates. to prevent collapsing of the slotted portion of the pin so as'to insure that the 5 full circumference of the pin will at alltimes have bearing in the receiver and thereby prevent wobbling of the pin. It will be clear that the tension of the spring can be increased or decreased to suit the requirements of a particular firearm by simply removing the screw 14; then shifting the pin P to disengage its head 10 from the socket 11; then rotating the pin until the desired adjustment of the tension is accomplished.

Referring to Figs. 4 and 5 have illustrated a modified form of my invention in which the hammer pin P is identical with the pin P and the spring S is constructed from a single length of Wire to provide a pair of flat coils l7 spaced apart to receive therebetween the hammer H, the outer end of the coils being connected by a straight transverse portion 18 and adapted to bear, against the rear edge of the hammer as shown, the inner end of the coils being a'ngularly bent as indicated at 19, and adapted to be received in the slot of the pin P. Tension is placed upon the spring S by adjustment of the pin in the manner previously described and it will be clear that the engagement of the portion 18 of the spring with the hammer will cause the latter to be urged. to released position. 7

From the foregoing description it will be manifest that I have provided an extremely simple, compact and dependable spring action capable of being applied to all types of, firearms with but slight modification of their construction. Furthermore my invention reduces the number of parts and hence the cost of manufacture of spring actions to a minimum, and without sacrificing the dependability, positiveness of action, and long life which a spring action-should have.

Although I have herein shown only two spring actions for firearm hammers embodying my invention, it is to be understood that various changes and modifications may be made therein without departing from the spirit of the invention and the spirit and scope of the appended claims.

I claim as my invention:

1. In a firearm, a pivot pin slotted longitudinally and adapted to be mounted in the receiver of the firearm, a hammer pivotally mounted on the pin and having its'pivoted end bifurcated, a torsional spring mounted on said pin and received in said bifurcation of the hammer with the outer end of the spring engaging the hammer and the inner end angularly bent and disposed in said slot of the pin, saidpin having a head at one end adapted to seat within a pocket in the receiver to lock the pin against rotary movement, and a screw threaded into the .other end of the pin and adapted to engage the angular-1y bent inner end of the spring, where- .by said head and screw cooperate to prevent longitudinal displacement of the pin.

2. In a firearm, a hammer, a torsional spring therefor, and a pin fixed against rotation and upon which the hammer is mounted for pivotal movement, said spring mounted on-said pin with one of its ends fixed to the latter and its other end engaging the hammer so as to urge the latter to one position, the pivoted end of the hammer being bifurcated to receive the spring, and the pin being slotted longitudinally to receive the first said end of the spring.

3. In a firearm, a bifurcated hammer, a pin fixed against rotation and upon which the hammer is pivotally mounted, and a torsional spring mounted on said pin in said bifurcation of the hammer and having one of its ends fixed to the pin and its other end engaging the hammer to urge the latter in one direction.

4. In a firearm, a pivot pin slotted longitudinally from one end and adapted to be mounted in the receiver of the firearm, the pin having a non-circular head at its other end adapted to seat within a pocket in the receiver to lock the pin against rotary movement, a hammer pivotally mounted on the pin, a torsional spring mounted on the pinand having one end fixed to the pinand its other end engaging the hammer to normally urge the latter to rotate in one direction, and means for preventing collapsing of the slotted portion of the pin under the tension of the spring so as to insure that the full circumference of the pin will have bearing in the receiver and thereby prevent wobbling of the 5. In a firearm, a slotted pivot pin adapted to be mounted in the receiver of the firearm, the pin having a non-circular head at onev end adapted to seat within a pocket in the receiver to lock the pinagainst'rotary movement, abifurcated hammer pivotally mounted on the pin, a torsional sprin mounted on the. pin in said bifurcation 0% the hammer and having one end extending into the slotted portion of the pin and its other end engaging the hammer to normally urge the latter to rotate in one direction, and means forpreventing collapsing of the slotted portion of the pin under the tension of the spring so as to insure that the full circumference of the pin will have bearing in the receiver and thereb prevent wobblin of the in.

A CHIBALD- R. B INKE HOFF. 

